Age-dependent reliability model considering effects of maintenance and working conditions

Nowadays, there is some doubt about building new nuclear power plants (NPPs ). Instead, there is a growing interest in analyzing the possibility to ext end current NPP operation, where life management programs play an important role. The evolution of the NPP safety depends on the evolution of the reli ability of its safety components, which, in turn, is a function of their ag e along the NPP operational life. In this paper, a new age-dependent reliab ility model is presented, which includes parameters related to surveillance and maintenance effectiveness and working conditions of the equipment, bot h environmental and operational. This model may be used to support NPP life management and life extension programs, by improving or optimizing surveil lance and maintenance tasks using risk and cost models based on such an age -dependent reliability model. The results of the sensitivity study in the e xample application show that the selection of the most appropriate maintena nce strategy would directly depend on the previous parameters. Then, very i mportant differences are expected to appear under certain circumstances, pa rticularly, in comparison with other models that do not consider maintenanc e effectiveness and working conditions simultaneously. (C) 1999 Elsevier Sc ience Ltd. All rights reserved.